Electric switch



July 2, 1935. G, LEMMQN ET AL 7 2,006,866

ELECTRIC SWITCH Filed Dec. 30, 1951 INVENTOR Z NXM Patented July 2, 1935 UNITED STATES PATENT oFFics j 2,005,86 I ELECTRIC swi'roH George N. Lemmon, 'Homewood, and Harry H. I Knowles, Birmingham, Ala.

Application December 30, 1931, SerialNo. 583,802 8 Claims. (01. 200-48) The main object of our invention is to'provide a contact which shall have a slight but positive sliding action between the conducting members as they come together when closing the circuit. A further object is to provide a simplified support for. the flexible conductor which is part of the switch.

Referring to the drawing, Fig. 1 shows in elevation a side-break switch embodying our device; Fig. 2 is an elevation of our rocker-type switch. Both of these designs are well known to those familiar with the art. Fig. 3 shows in partial section an enlarged detail of the contacts in the opening or closing position, and Fig. 4 is a similar detail with the contacts closed.

In Fig. l, a base I carries a stationary insulator 2 and a movable insulator 3 which is rotated by the crank 3. Securely fastened to 3 is a conducting arm 4, and the conductor I l is connected to 4 by a pivot and the flexible lead l3.

On the insulator 2 is a housing I0 within which is a movable contact member which engages with the end of 4. Flexible conductors ll furnish a positive connection between this movable contact member and the line conductor l2.

In Fig. 2, the base i carries two stationary insulators 2 and 20 and a movable insulator 3. This is attachedto the rockable square shaft 25 and carries a conductor 4 with a contacting terminal 5. Insulator 2 carries the housing 1, pivoted about the pin 9 and supporting the movable contact member 6, which isbiased outwardly by the springs 8. The housing 1 is biased to the angular position shown in Fig. 3 by the spring 24, and the stop 25 limits the motion of l to'the desired travel. As the switch is closed, I and 4 are brought into the straight line position shown in Fig. 4. This action is quite similar to the action shown in our Patent No. 1,955,132 issued April 1'7, 1934. I

However, the contacts 5 and 6 come together before'the position shown in Fig. 4 is reached, and as the two engaging faces have curves with the same radius, they engage over a considerable part of the curve. Further motion of the conductor 4 towards the closed position causes a sliding action of 5 over the surface of 6, which confrom sticking to 5 where they first touch each other, and makes 6 and 5 slide around on one sponding pivot on top of the insulator 3.

another as the switch is being closed the rest of the way. I

This sliding action tends to rub off any dirt or corrosion, and this insures a good contact .between the parts.

For switches of large capacities, two ormore members 6, each with its flexible conductors-H and its springs 8, are mounted in a single housing 1, and the contact .end 5 is lengthened into a cylindrical surface which engages with all of the members 5. Each of these members 6 makes its own contact with 5, independently of the other members, and the conductors ll give proper connection with the line l2. In the side-break switch shown in Fig. 1 parts similar to 6, l, 8 and 9 are mounted under the housing Ill; and these parts in both switches function similarly.

If the rocker-type of switch is employed, as shown in Fig. 3, then we support the flexible conductor I3 by means of an arm I5 which is pivoted lat I6 and carries a ring I! through which the conductor l3 passes freely. It is quite customary to support this long flexible lead, which is not self-supporting, by a pantograph consisting of two arms, one like I5 except for the stop 18, and another which is pivoted to the cap on insulator 3 and is also pivoted to IE at its end ll. Such a pantograph is made longer than the maximum straight distance from the pivot I8 to the corre- Therefore the pantograph cannot dropdown, and so the conductor I3 is held up in a safe. position and is not allowed to sag down towards the grounded metal base, whether the switch is open or closed.

.We support the flexible conductor safely, and

have the wide, free motion of a pantograph while using only one supporting arm. A stop I8 rests against the head IQ of th insulator 20 and limits the downward motion of 15. When the insulator 3 is rocked backwards towards 2B, the switch is opened and the arm 15 takes the position 2| as the conductor I3 is pushed back and takes'the position 22. In this way, the flexible conductor is held up in a safe position without the use of a complete pantograph such as is generally used for this purpose.

We claim:

1. In an electric switch, a stationary conducting member, a flexible conductor connected therewith and extending away from said member, a

rigid arm pivotally supported at one end only, said arm supporting the said flexible conductor.

2. In an'electric switch, a-stationary insulated support and a movable insulated support, a flexible conductor between them, and a rigid member which is pivotally supported at one end only and which is arranged to hold up the center portion of the said flexible conductor.

3. In an electric switch, a stationary conducting member, a flexible conductor connected therewith and extending away from said member, an arm pivotally supported at one end only, by the said stationary member, said arm supporting the said flexible conductor.

4. In an electric switch, a stationary conducting member, a pivotally mounted arm thereon, a stop limiting the downward travel of the arm,

and a flexible conductor supported by the-free end of the arm.

5. In an electric switch, two movable members with abutting contact faces in a plane transverse,

to the plane of movement, the face of one member in its normal closed position extending beyond the face of the other member in its normal closed position, together with means to allow one member to be pressed back from its normal position.

6. In an electric switch, two movable members with abutting contact faces in a plane transverse to the plane of movement, the face of one mem-' her in its normal closed position extending'beyond theface of the other member in its normal closed position, together with means to bring the said faces into contact before the members reach the fully closed position of the switch, and to slide the faces over one another as they move into the fully closed position.

'7. In an electric switch, two movable members with curved abutting contact faces in a plane transverse to the plane of movement, one face being curved inwardly and the other curved outwardly, the face of one member in its normal closed position extending beyond thepface of the other member in its normal closed position, together with means to allow one member to be pressed back from its normal position, and with means to bring the said faces into contact before the members reach the fully closed position, and to slide the faces over one another as they move into the fully closed position of the switch.

8. In an electric switch, a movable conducting member having an outwardly curved contact face across its end, a second movable conducting member having aninwardly curved contact face in juxtaposition to the said first contact face, together with means to bring the said faces into contact and rub them together, as the switch is being closed.

4 GEORGE N. LEMMON. HARRY H. KNOWLES. 

